A Compact, Low Profile Log-Periodic Monopole Array with an Ultra-Wideband Stripline Transition

A Compact, Low Profile Log-Periodic Monopole Array with an ultra-wideband stripline transition is proposed in this paper. It consists of 7 top hat loaded monopole elements, which ensures the whole structure to be compact and low profile. The ultra-wideband stripline transition is used to keep the consistence between feeding direction and antenna radiation direction. The proposed antenna has an extremely low profile of 0.043$\lambda_{L}$, and a compact size of 0.60 $\lambda_{L}$×0.16$\lambda_{L}$ in transverse dimension, ($\lambda_{L}$ is the free-space wavelength at the b west operating frequency). Simulation results shows that from 0.6-3.1 GHz (135%) in terms of VSWR <3 and max gain of 6.5dBi is obtained.